Photographic film units are subject to a number of competing considerations. A bare filmstrip is difficult to handle and is not light-tight by itself. Type 120 film adds a spool and opaque backing paper. Another roll film, Type 220, has a spool, an opaque paper leader, and an opaque paper trailer attached to the filmstrip. These film units are compact and simple, but must be used with care to ensure that the paper and filmstrip do not inadvertently uncoil and become exposed to light. Cartridge films such as Type 135, Type 126, Type 110, and Advanced Photo System.TM. add a one or two chamber shell over a spool. These film units are more complex and larger relative to the filmstrip enclosed than Type 120 and Type 220, but can be used with less care to ensure that the filmstrip is kept light-tight. One-time use cameras add camera features to a simpler filmstrip or film unit and are subject to similar trade-offs. A one-time use camera that includes a film cartridge requires less care in exposed film removal than a one-time use camera that uses roll film, but is larger and more complex.
It would thus be desirable to provide an improved film unit that is compact and relatively simple, but combines good light-tightness with ease of use.